1. The Irish Longitudinal Study on Ageing (TILDA), Department of Medical Gerontology, Trinity College Dublin , Dublin , Ireland
2. Center for Research in Economics and Statistics (CREST), ENSAE, Institut Polytechnique de Paris , Palaiseau , France
3. Research Department of Epidemiology and Public Health, University College London , London , UK
4. Mercer’s Institute for Successful Ageing, St James’s Hospital , Dublin , Ireland